Effluent treatment method for membrane separation activated sludge, effluent treatment apparatus, and effluent treatment system management program

Abstract

Provided is an effluent treatment method based on a membrane separation activated sludge method, the effluent treatment method being characterized in that activated sludge collected from a membrane separation activated sludge tank is observed by an optical means, image processing is performed, and effluent treatment conditions are controlled in accordance with the results thereof.

The invention claimed is: 
     
       1. A wastewater treatment method utilizing a membrane separation activated-sludge method, comprising the steps of:
 taking an image of an activated sludge collected from a membrane separation activated-sludge tank; 
 processing the image taken; and 
 comparing a control parameter determined from information of the processed image with a preset control reference range to assess an operating state of the membrane separation activated-sludge tank, said information includes at least one of hue, lightness, saturation, number of pixels, chromaticity and brightness, 
 wherein the control parameter is an aqueous-phase suspended matter amount in the activated sludge, and 
 wherein the method further comprises: 
 calculating a total area of floc regions each having an area not larger than a predetermined value and surrounded by an aqueous-phase region, per unit area of a field of view, wherein floc regions that each have an area larger than the predetermined value are excluded from said step of calculating the total area; and 
 comparing at least one of the calculated value and a change amount in the calculated value with a lapse of time, with the preset control reference range to assess the operating state of the membrane separation activated-sludge tank. 
 
     
     
       2. The wastewater treatment method according to  claim 1 , wherein, in taking the image of the activated sludge collected from the membrane separation activated-sludge tank, the image is taken after degassing and/or stirring at least any one of a liquid mixture obtained by mixing the activated sludge with a membrane filtrate water, and an aqueous phase portion obtained by centrifuging the activated sludge. 
     
     
       3. The wastewater treatment method according to  claim 1 , further comprising:
 when the control parameter has been assessed to be outside the control reference range, outputting at least one of an alarm and a control information regarding a wastewater treatment condition. 
 
     
     
       4. The wastewater treatment method according to  claim 3 , wherein the wastewater treatment condition, regarding which at least one of the alarm and the control information is output when the control parameter has been assessed to be outside the control reference range, is at least any one of the following:
 (A) concentration of inflow water to be treated and inflow rate, 
 (B) filtration rate, 
 (C) filtration period or filtration suspension period, 
 (D) aeration-air feed rate or aeration period, 
 (E) nutrient salt addition amount, 
 (F) chemical addition amount, 
 (G) amount of activated sludge, 
 (H) treated-water return rate, 
 (I) operating conditions for pretreatment step, 
 (J) operating conditions for post-treatment step, 
 (K) temperature regulation conditions for activated-sludge tank, 
 (L) operating conditions for membrane elements, 
 (M) cleaning conditions for membrane elements, and 
 (N) cleaning conditions for aeration tubes. 
 
     
     
       5. The wastewater treatment method according to  claim 3 , wherein the assessment is made at a place which is remote from a place where the image of the activated sludge collected from the membrane separation activated-sludge tank is taken, the place where the image of the activated sludge collected from the membrane separation activated-sludge tank is taken being connected to said place where the assessment is made by a communication appliance, thereby outputting at least one of the alarm and the control information. 
     
     
       6. The wastewater treatment method according to  claim 3 , further comprising controlling the wastewater treatment condition on the basis of the control information output. 
     
     
       7. The wastewater treatment method according to  claim 6 , further comprising the steps of:
 processing the image to assess the aqueous-phase suspended matter amount in the activated sludge; 
 when the result is higher than the preset control reference range, performing an operation for reducing at least one of a water-to-be-treated inflow rate and a filtration rate; and 
 when the result is lower than the preset control reference range, performing an operation for increasing at least one of the water-to-be-treated inflow rate and the filtration rate.